Control system for washing machines



May 12, 1959 a BLOOM A 2,885,879

CONTROL SYSTEM FOR WASHING MACHINES Filqd April 17; 1955 INVENTOR..fm/Vl' fl. 5100/]! BY 420W Yin- 0454 United States Patent CONTROLSYSTEM FOR WASHING MACHINES Stanley B. Bloom, Philadelphia, Pa.,assignor to Philco Corporation, Philadelphia, Pa., a corporation ofPennsylvania Application April 17, 1956, Serial No. 578,676

4 Claims. (Cl. 68-207) The invention herein described and claimedrelates generally to control systems and pertains more particularly tomeans for controlling the quantity of liquid delivered to a container.Specifically, the invention has to do with adjustable means forautomatically shutting 0E the flow of liquid to a container when theliquid fed thereto reaches a predetermined level.

Although suitable for use with various types of equipment adapted tofill different kinds of receptacles or containers with most any kind ofliquid, the novel arrangement of this invention is especially usefulwhen applied to clothes washing machines of the variety in which wateris introduced into a washing basket to fill the same to a predeterminedlevel, whereupon the machine proceeds to function automatically to washand damp-dry clothes by going through successive agitating, rinsing andliquid-extracting cycles.

In a machine of this type, it is important that the washing basket besupplied with Water in an amount sufficient to insure adequate washingof the clothes. It is also important, for economical reasons, that thesupply of water be automatically shut off when it reaches a level whichis selectively determined for proper washing of clothes in given averageloads.

Different known arrangements employing either floats orpressure-responsive devices as means for controlling the water level inwashing machines, have been devised to realize these desirable ends.While many of these known arrangements serve their purpose adequately,nevertheless they have certain disadvantages, mostly due to the factthat such known arrangements depend on wash water being brought intodirect contact with the float or pressureresponsive control means. As aresult, scum, dirt and the like, tend to accumulate about the controlmeans and to interfere with its proper function.

Accordingly, it is an object of the present invention to overcome theabove mentioned disadvantages by providing a novel arrangement which,although controlled in response to water in the washing machine,obviates the necessity of subjecting the control means to direct contactwith the water.

It is also an object of the present invention to provide an improvedarrangement for controlling the level of water in an automatic washingmachine, the arrangement being such that it requires few parts andnecessitates no major structural changes in the basic construction ofthe machine.

A characteristic feature of the invention resides in the provision of anovel combination of elements in which simplified control means functionto efiect automatic interruption of the flow of water to the washingmachine when the clothes washing tub or basket thereof is filled to apredetermined level, said device being responsive to a small proportionof the water supplied to the machine so as to effect an appreciablesaving in water consumption.

The invention is further characterized in that the novel combination ofelements includes a pressure activated 2,885,879 Patented May 12, 1959flow-controlling device operating in response to air rather than waterdisplacement thereby alleviating possible illeffects resulting frominundation of delicate parts of such a device.

An arrangement according to the present invention has the furtheradvantage that the circuit or system employed to effect operation of thepressure-responsive device, does not require sealed gas-containingconduit means; The arj rangement is sudh that the operating system isrecharged with air at atmospheric pressure after each operation, so thatminor leakage does not present a problem.

Generally stated, the above noted objects and features of the inventionare achieved by a novel cooperative arrangement of water-flow dividingmeans, water accumulating means, air trapping means and air pressuresensing means. In this arrangement, the sensing means operates to stopdelivery of water to the flow dividing means in response to an increasein air pressure due to displacement of air in the trapping means byreason of water fed thereto from the accumulating means.

According to a specific embodiment of the invention, the wateraccumulating means and air trapping means communicate with the inletside of a drain pump which, when operating, removes the water to releasethe increased pressure within the sensing means.

In a more subordinate aspect, the invention includes improved andadvantageous features of construction, combination and arrangement ofparts, all of which will be fully set (forth hereinafter.

As indicated hereinabove, the liquid feed control a-rrangementcontemplated by the present invention may be utilized with various typesof equipment. However, because the principles of the invention areparticularly applicable to clothes washing machines, the specificembodiment herein given by way of example, is illustrated and will bedescribed in connection with such a machine.

Accordingly, the single figure in the accompanying drawing is afragmentary sectional view of a portion of an automatic agitator-typewashing machine, certain elements of the control arrangement beingrepresented diagrammatically for simplicity of illustration.

Having more particular reference to the drawing, there is illustrated adomestic clothes washing machine which includes an outer casing orcabinet 10 housing a fixed tub 11 which encircles a rotatableimperforate washing basket 12. The cabinet has an open top portion 14which is provided with a cover 15 to give access to said washingbalsket.

Water at proper temperature is supplied to the washing basket throughconventional means including a hot-water conduit 16, a cold-waterconduit 17, a self-closing water valve 18 and a discharge nozzle 19, thelatter directing water into the basket 12 through the open top thereof.Clothes are washed in the basket 12 by action of a bladed agitator 20and after washing, are rinsed and then dampdried by spinning of thebasket. During spinning, water is expelled from the basket 12 into tub11 through a row of apertures 21 adjacent the top portion of saidbasket. From the tub 11, water passes out through a drain opening 22into an inlet 23 of a pump 24, the outlet 25 of which communicates witha discharge duct 26, the pump being motor driven by means ofbelt-and-pulley means 24a.

According to the present invention, there is provided a selectivelyadjustable control arrangement for automatically terminating the feed ofwater to the basket 12 when the water therein reaches a predeterminedhigher 01' lower level to accommodate a full or less than full load ofclothes to be washed in said basket. In particular accordance with theinvention, the control arrangement includes: a water flow-dividingchamber 27 disposed between the solenoid-operated mixing valve 18 andthe discharging nozzle 1-9; a water-accumulating chamber 28communicating with the drain opening 22 of the tub 11 and havingpassageway 29 leading to the inlet 23 of the pump 24; an airtrappingchamber interposed in the passageway 29 between the water-accumulatingchamber 28 and the drain pump 24; and an air-pressure responsive switchdevice 31 connected with the air-trapping cham her through an air line32.

As shown in the drawing, the flow-dividing chamber is formed with aninlet 33 and with a larger outlet 34 and a smaller outlet 35, the inlet33 communicating with the mixing valve 18 to receive water therefrom.The larger outlet 34 is disposed to discharge part of the water from thevalve 18 into the nozzle 19, and the smaller outlet 35 communicates withan opening 36 in the machine tub 11 to discharge another part of thewater from said valve into said tub. The smaller outlet is such that theamount of water flowing therefrom is proportionate to the amount ofwater which flows out of the larger outlet and, in practice, the sizeand position of these outlets with respect to each other are such thatthe level of the water in the relatively small accumulating chamber 28and trapping chamber 30 rises at approximately the same rate as thelevel of the water in the relatively large basket 12.

The switch device 31 functions to etfect stoppage of the water flow tothe machine. This switch device comprises a housing 37 enclosing aflexible diaphragm 38 and a pair of electrical contacts 39 and 40. Asrepresented in the drawing, the switch device is of the normally openvariety in which the contact 39 is conveniently associated with one sideof the diaphragm 38 so as to be moved into engagement with the othercontact 40 in response to air displacement within an enclosed space 41on the other side of the diaphragm. The contact 40, as also representedin the drawing, is adjustable in various positions with respect to thecontact 39, so that the pressure, and therefore the time required toefiect closing of the switch is increased or decreased. For thatpurpose, there is conveniently provided a rotatable stepped cam 42arranged to bear upon a spring-urged slidable plunger 43 associated withthe contact 40, said cam being advantageously rotated by means of amanually operable knob or dial 44, as sociated with suitable indicatingmeans bearing appropriate position-designating marks.

In the illustrated embodiment, three such marks are represented by thealphabetical characters F, M and L, and the cam 42 has three stepportions 45, 46 and 47 of different radial displacement to locate thecontact 40 in three different operating positions F M and Lcorresponding to the setting positions of the dial 44, to effectselective adjustment for automatically terminating the feed of waterwhen it reaches the proper level required for adequately washing a full,a medium or a light load of clothes. With an arrangement of this kind,the feed of water would stop when water in the tub 12 reaches one ofthree levels which are represented at F M and L2- The contacts 39 and 40of the switch 31 are electrically connected in the control circuit 48 ofthe machine, which circuit includes the usual driving motor 49 and asolenoid 50, the latter serving to control operation of the agitator 20,through the agency of transmission means which is diagrammatically shownat T, said transmission means being driven in any convenient fashion, bythe motor 49. The motor is coupled in the usual manner with the pump 24and with the transmission means, as is diagrammatically represented at Cand C respectively. As is also customary, the transmission is connectedwith the control solenoid 50 and with the shaft of the agitator 20, asis diagrammatically represented at C and C respectively. As seen in thedrawing, said switch contacts are in shunt with the solenoid valve 18which is in series with said motor 49 and said solenoid 50. It will beunderstood that when the switch 31 is open, the relatively highimpedance of the motor circuit causes most of the voltage supplied byAG. line 52 to be applied to the solenoid valve 18 which is therebymaintained in open position for admitting water to the machine. Duringthis condition of operation current flows through the motor 49 andclutch solenoid 50, but the voltage is insufiicient to operate the same.However, when the switch 31 is closed, the solenoid of the self-closingvalve 18 is by-passed so that said valve closes to interrupt the flow ofwater to the machine, whereas the motor 49 and agitator solenoid 50 areplaced across the line 52 and operate in parallel under the full voltagesupplied by said line.

As is customary, control of the machine through its washing, rinsing andspinning cycles is governed by means of a timer 51 of knownconstruction. This timer is coupled in the circuit 48 to becomeenergized upon closing of the switch 31. The timer is in shunt withmotor and with the agitator solenoid. Therefore, the timer runs wheneversaid motor and solenoid are energized, that is, when the seriesimpedance of solenoid valve 18 is removed. Suitable linkage connects theagitator solenoid with an auxiliary switch 54 which serves to insuredisruption of the flow of current to the solenoid valve 18 when thepressure on the bellows 38 drops as a result of operation of the pump 24by the motor 49, and which also serves to reestablish the How of currentto said valve when the time comes for water to be again fed to themachine.

When using a washing machine incorporating the waterfeed controllingarrangement of this invention, the dial 44 is normally moved to theposition corresponding to the load of clothes to be washed. In thedrawing, the dial 44 is set at the intermediate position M which is theposition for washing a medium load of clothes. in this position, thestep 46 of the cam 42 adjusts the plunger 43 to locate the contact 43 inthe intermediate position M Upon starting the machine, the solenoidvalve 18 is energized so that Water flows into the chamber 27. From thischamber, a greater part of the water passes through the larger outlet 34and nozzle 19 into the Washing basket 12, and a proportionately lesserpart oi the water flows out through the restricted outlet 35 into thetub 11 and thence through the drain outlet 22 into the accumulatingchamber 28. During the time that water is introduced into the machine,the pump 24 remains idle so that water from said accumulating chamberbacks up into the air-trapping chamber 30. As the water level rises inthe washing basket and in the accumulating chamber, a proportionatewater rise occurs in said trapping chamber 30 causing displacement ofthe air therein to increase the pressure within the enclosed space 41behind the flexible diaphragm 38 of the switch device 31. Thus, in theoperational setting illustrated, when the level M in the basket 12, thelevel M in the accumulating chamber 28 and the level M in the trappingchamber 30 are reached, then the pressure on the flexible diaphragm 38causes contact 39 to come into engagement with the contact 40 adjustedin position M When this occurs, the valve 18 shuts ofi the flow of waterto the washing basket, and the timer 51 takes over so that the washingmachine goes through its usual washing, rinsing and spinning cycles.

When the pump 24 is energized, water is withdrawn from the accumulatingchamber 28 as well as from the air trapping chamber 30, thus reducingthe pressure on the diaphragm 38 so that the switch 31 is automaticallyreset for subsequent use. This pressure reduction would normally act tocause reenergization of the solenoid valve 18, however, this action isprevented by function of the auxiliary switch 54 under control of theagitator solenoid 50.

In order to adapt the machine for washing a full load of clothes, thedial is set to the F position thereby moving the contact 40 to the Fposition, farther away from contact 39, so that water in the tub 12 willrise to the higher'level before interruption of the water flow, therebyproviding sufficient water to wash a full load of clothes.

To wash a light load of clothes, the dial is set to the L positionthereby moving the contact 40 to the L position, nearer to the contact39, so that the valve 18 closes when the water in the tub 12 reaches thelowermost level.

While a dial has been described as convenient means for adjusting orsetting the operation of the water flow control mechanism, it will beappreciated that other suitable means, for instance, push-buttonarrangements, lever operated devices or similarly known contrivances,may be employed for that purpose. Also, it will be apparent that theflow dividing chamber herein described as a separate element, could bereadily incorporated in the body of the water inlet valve. Moreover,while three positions of the control device have been described, it willbe recognized that the number of positions can be varied to provide forfilling of the tub to any one of several desirable predetermined levelsto accommodate various loads of clothes. It will furthermore beunderstood that the air trapping chamber can be arranged to communicatewith a lower part of the water accumulating chamher without beinginterposed in a conduit leading from said accumulating chamber to thedrain pump.

I claim:

1. A level control system comprising a receptacle adapted to retainliquid, a liquid accumulating chamber separated from said receptacle, anelectrically operated liquid supplying valve, flow dividing means fordelivering liquid from said valve to said receptacle and chamber, saiddividing means including two outlets of different size, the outlet oflarger size being disposed to discharge liquid in a greater amount tosaid receptacle and the outlet of smaller size being disposed todischarge liquid in a proportionately lesser amount to said chamber, apressure responsive switch for controlling the operation of said valve,an air trap communicating with said switch and with a lower portion ofsaid chamber in such manner that liquid in said chamber passes into saidtrap and displaces the air therein to cause actuation of said switch tocontrol the operation of said valve, means for withdrawing the liquidfrom said trap and chamber, and means for rendering said withdrawingmeans ineffective during liquid-delivering operation of said valve andfor rendering said withdrawing means effective upon cessation of saidoperation.

2. A system as set forth in claim 1, in which the means for withdrawingthe liquid includes a motor and a pump driven thereby, said motor beingelectrically associated with the mentioned switch.

3. In a Washing machine, the combination of a rotatable basket adaptedto retain water and to receive clothes to be washed, a tub surroundingsaid basket and having a water accumulating portion, an electricallyoperated water supplying valve, a water flow dividing chamber fordelivering Water from said valve to said basket and tub, said chamberhaving a larger outlet to discharge a larger amount of water fordelivery to said basket and also having another outlet of predeterminedsmaller size as compared to said larger outlet to discharge aproportionately lesser amount of water for delivery to said tub portion,a pump for withdrawing the water from said tub portion, a pressureresponsive switch, an air trap communicating with said switch, means forpassing water from said tub portion to said trap to increase the airpressure on said switch, a motor for driving said pump, and circuitmeans electrically connecting said switch with said valve and motor toinitiate operation of said pump simultaneously with termination of theoperation of said valve.

4. In a washing machine, the combination of a rotatable basket adaptedto retain water and to receive clothes to be washed, a tub surroundingsaid basket and having a water accumulating portion, an electricallyoperated water supplying valve, a water flow dividing chamber fordelivering water from said valve to said basket and tub, said chamberhaving a larger outlet to discharge a larger amount of water fordelivery to said basket and also having another outlet of predeterminedsmaller size as compared to said larger outlet to discharge aproportionately lesser amount of water for delivery to said tub portion,a pressure responsive switch, an air trap communicating with saidswitch, means for passing water from said tub portion to said trap tovary the air pressure on said switch and thereby operate the same, andcircuit means electrically connecting said switch with said valve toactuate the latter in response to operation of said switch.

References Cited in the file of this patent UNITED STATES PATENTS1,223,584 Huebsch et al. Apr. 24, 1917 2,326,067 Rohr Aug. 3, 19432,563,738 Oliver Aug. 7, 1951 2,592,314 Morton Apr. 8, 1952 2,752,769Clark July 3, 1956 2,812,152 Wyatt Nov. 5, 1957

